The field of the invention pertains to compound bows for archery and, in particular, to devices for improving the competitive accuracy of the bow and archer by improving the repeatability of the draw of the arrow.
Arrow actuated means to signal to the archer that the arrow is sufficiently drawn are disclosed in several U.S. patents. U.S. Pat. No. 3,450,122 discloses a magnetic circuit through an electric switch. The magnetic circuit is closed by magnetically permeable material on the arrow to thereby close the electric switch and illuminate a light adjacent the sight. The device requires special arrows having a magnetic material adjacent the arrow tip and located for the proper draw of the arrow.
In U.S. Pat. No. 3,867,920 an electrical conductor at the proper location adjacent the arrow tip for proper draw completes an electric circuit through contacts in the arrow rest of the bow. With contact an electric signal light mounted on the bow illuminates.
U.S. Pat. No. 4,134,383 discloses a bow drawing indicator comprising a spring arm and electrical contacts mounted on the bow and actuatable to illuminate one or both of a pair of signal lights. The spring arm is attached to a connector cord in turn attached to a pass of the bow string. A specially constructed arrow is not required to actuate the signal lights.
In U.S. Pat. No. 4,179,613 a photoelectric sensor is used to signal the full draw of the arrow by sensing the tip of the arrow. Sensing the arrow tip causes a signal light on the bow to illuminate.
U.S. Pat. No. 4,421,093 discloses a pair of draw stop members each connected to a cable pass or flight that moves opposite the other. The draw string is pulled back until the draw stop members abut one another signalling manually to the archer that the draw string has been pulled to the desired length. However, there is no indicator light or sound to tell the archer the instant he is at full draw, or whether the draw is being maintained.
In addition, devices are available that produce an audible click upon full draw of the arrow, however, such devices cannot be reset without fully releasing the arrow from the bow.
With a view towards simplifying the electrical devices of the prior art and obtaining better repeatability of shooting form and the subsequent improvement in accuracy, applicant has invented the archery training aids disclosed and claimed below.